I have an 08 with the 3.7L and have the stage 2 jetchip. I believe that is the only chip available right now. The stage 1 is garbage and works only at WOT. The stage 2 works great and at all throttle positions. I had to do a custom free flow exhaust and run 91 octane but it is well worth it. I promise you with the stage 2 the computer will not set itself back to factory with the stage 2. They say to use a 180 thermostat but I don`t and it runds fine. Also ramair makes a intake sensor performance mod that a lot of people have had good luck with. If you do any tuning just make sure to use 91 octane and a free flow exhaust. I hope this helps.
Here is the link to the ramair site.
AirRam - Cold Air Induction System